EAGER: Scanning Ultrasound Probe for Semiconductor Sub-Surface Metrology

EAGER：用于半导体次表面计量的扫描超声波探头

• 批准号: 1842662
• 负责人: Gajendra Shekhawat
• 金额: $ 11万
• 依托单位: Northwestern University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1842662&HistoricalAwards=false
• 关键词: EAGER; Scanning; Ultrasound; Probe; Semiconductor

Non-technical:There is an acute need to image semiconductor devices at nanometer scales below the surface. This will make it possible to identify buried defects and perform failure analysis in two- and three-dimensional structures such as micro-electromechanical systems (MEMS). Current nanoscale subsurface imaging techniques require extensive sample preparation, are exceptionally slow, and require expensive equipment. Or they are simply unable to image opaque samples. The solution is a tool which provides non-destructive, high throughput nanoscale imaging of buried defects at a reasonable cost. This project will combine scanning probe microscopy with ultrasound holography to reveal and characterize subsurface features with nanoscale resolution in three dimensions. In this technology, a cantilever monitors acoustic waves that travel along the surface. Perturbations to the amplitude and phase of these waves carry information about structures beneath and near the surface. These variations are detected as small differences in frequency and phase, resulting in beats that are detected by the cantilever. These variations are then used to create spatial mappings generated by subsurface and near-surface features and defects as the cantilever scans across the surface. The ultimate aim is to integrate scanning probe microscopy hardware with functional electronics into field-programmable gate arrays, configurable integrated circuits. The project promises to open new vistas in non-destructive imaging of semiconductor devices and structures. Once developed, the technology will be made available to other institutions, broadening the user base to include physical sciences, engineering and related fields. The PI will integrate results from this project into undergraduate courses and highlight how the principles of engineering and physical science impact materials and device research. Active participation of underrepresented groups will be promoted through classroom visits to elementary schools through the Science Chicago program.Technical:There is an acute and timely need for innovative imaging modalities in semiconductor industries. These are especially needed to identify the buried defects and delamination and provide failure analysis in both two- and three-dimensional structures. These include devices based on micro-electromechanical systems (MEMS) and interconnects. This project will develop "Scanning Thickness Resonance Acoustic Microscopy" for sub-surface inspection and failure analysis. Current nanoscale subsurface imaging techniques are unable to probe optically opaque samples or require extensive and time consuming sample preparation, are exceptionally slow, and require expensive metrology equipment. The solution is a tool which provides non-destructive, high throughput nanoscale imaging of buried defects, and that can be widely deployed at multiple points in the research and development cycle, at a reasonable cost. Anticipated applications will identify buried nanostructures in semiconductor, MEMS, and low-K dielectric materials both in 2D and 3D geometries. This innovative technology will bring transformative research in identifying the failure analysis and buried defects both in 2D and 3D materials stacks in complex three-dimensional devices and structural geometries with nanometer scale resolution. In this technology, the cantilever monitors the perturbation to the surface acoustic waves, especially their phase, which carry information about embedded or buried sub-structures reflected in the scattering of specimen acoustic waves due to the difference in their respective viscoelastic properties. Variations in the amplitude and phase of the bulk wave due to the presence of the sub-surface nanostructures/defects as well as the variations in near surface affect the amplitude and the phase of the difference frequency signal (beats) which is detected by cantilever. These variations are used to create spatial mappings generated by subsurface and near-surface features/defects. To realize these efforts requires a way to combine scanning probe microscopy hardware, functional electronics and its integration into field programmable gate arrays for simultaneous generation and detection of multiple harmonics.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

非技术层面：迫切需要在表面以下的纳米级对半导体器件进行成像。这将使识别埋藏的缺陷和进行二维和三维结构(如微电子机械系统(MEMS))的失效分析成为可能。目前的纳米级地下成像技术需要大量的样品准备，速度非常慢，并且需要昂贵的设备。或者他们根本无法对不透明的样品进行成像。该解决方案是一种以合理的成本提供埋藏缺陷的非破坏性、高通量纳米级成像的工具。该项目将结合扫描探针显微镜和超声全息术来揭示和表征三维纳米级分辨率的地下特征。在这项技术中，悬臂监测沿表面传播的声波。对这些波的幅度和相位的扰动携带了关于地表以下和附近的结构的信息。这些变化被检测为频率和相位的微小差异，导致由悬臂检测到的节拍。然后，当悬臂扫描表面时，这些变化被用来创建由地下和近地表特征和缺陷生成的空间映射。最终目标是将扫描探针显微镜硬件和功能电子设备集成到现场可编程门阵列、可配置集成电路中。该项目有望在半导体器件和结构的非破坏性成像方面开辟新的前景。一旦开发，这项技术将提供给其他机构，扩大用户基础，包括物理科学、工程和相关领域。PI将把这个项目的成果整合到本科课程中，并强调工程和物理科学的原理如何影响材料和设备研究。通过科学芝加哥计划对小学进行课堂访问，将促进未被充分代表的群体的积极参与。技术：半导体行业迫切而及时地需要创新的成像模式。尤其需要它们来识别埋藏的缺陷和分层，并提供二维和三维结构的失效分析。其中包括基于微电子机械系统(MEMS)和互连的设备。该项目将开发用于亚表面检测和故障分析的扫描厚度共振声学显微镜。目前的纳米级地下成像技术无法探测光学不透明的样品，也无法进行广泛而耗时的样品制备，速度非常慢，并且需要昂贵的计量设备。该解决方案是一种提供埋藏缺陷的非破坏性、高通量纳米级成像的工具，可以以合理的成本在研发周期的多个点广泛部署。预期的应用将在二维和三维几何结构中识别半导体、MEMS和低K介电材料中的掩埋纳米结构。这项创新技术将在识别复杂三维设备和纳米级结构几何中的2D和3D材料堆栈中的失效分析和隐藏缺陷方面带来变革性的研究。在这项技术中，悬臂梁监测表面声波的扰动，特别是它们的相位，这些扰动携带着由于样品声波各自粘弹性性质的不同而反映在样品声波散射中的嵌入或埋藏子结构的信息。由于亚表面纳米结构/缺陷的存在以及近表面的变化，体波的幅度和相位的变化会影响悬臂梁检测到的差频信号(节拍)的幅度和相位。这些变化用于创建由地下特征/缺陷和近地表特征/缺陷生成的空间映射。为了实现这些努力，需要一种将扫描探针显微镜硬件、功能电子学及其集成到现场可编程门阵列中以同时产生和检测多种谐波的方法。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。